Grinding wheels



vJune 18, 1957 Filed Aug. 15, 1956 A. A. MILLER GRINDING WHEELS 2 Sheets-Sheet 1 IN1/miran THM Mmm@ BYHAW Hrro/ewsx June 18, 1957 Filed ging. 15, 1956 A. A. MILLER GRINDING WHEELS FIG. a

2 Sheets-Sheet 2 myx/w linited States Patent GRINDING WHEELS Arthur A. Miller, McHenry, Ill., assignor to Arthur A. Miller and Lou C. Casanov, Waukegan, Ill.

Application August 15, 1956, Serial No. 604,141

6 Claims. (Cl. 51-191) yMy invention relates to improvements in grinding wheels.

My invention relates more particularly :to a grinding wheel provided with an air cushioned tread portion.

Grinding 'wheels of the type to ywhich this invention relates include a ring or band of abrasive such as sandpaper or the like mounted :on the periphery -or tread portion of the wheel, the tread portion being comparatively hard rubber, but so `constructed that a certain amount of resiliency is given to the sanding surface of the Wheel.

One `ot the principal objects of the present invention is to provide a relatively simple and inexpensive wheel of :this sort that is made of a relatively small number :of parts that are .easily assembled to form .a strong and sturdy device,

During the use of a sanding wheel, the wheel is caused to rotate at a relatively high velocity and the article to be sanded is applied against the sanding surface ofthe wheel. Due .to the friction between .the sanding surface of the wheel and the article applied thereto, there is a constan't tendency for the abrasive band forming ithe surta-ce Iof the wheel to .creep or move circumierentially :about the same. This movement is prevented in the device forming the subject matter yof the present invention in .a manner to be described hereinafter.

The principal object tof lthe present invention is to provide `an improved construction yof grinding wheel having a tread portion capable of guided movement during expansion tand provided with pin members adapted to move in elongated slots in the disc wheel members or plates in which the same is mounted.

A further object of the invention is to provide an proved construction of tread portion having a greater thickness :or backing throughout the center of the same between the disc whee-l or plate members, thereby providing a more eicient construction.

This :application shows improvements over the construction of grinding wheels shown and described in my copending application, Serial No. 600,019, .tiled July 25, 1956.

yOther 4objects Iand advantages will 'be more vapparent from the following description wherein reference is had to the accompanying drawings, upon which:

Fig. l is a side elevational view of a grinding or abrasive wheel constructed in accordance with my invention;

Fig. 2 is a plan sectional view thereof, taken generally on the line 2-2 of Fig. 1 .to show part :of the .grinding wheel lin cross-section and a portion thereof in plan View;

Fig. 3 is a fragmentary cross-sectional view of an abrasive wheel :of a larger size than that shown in Figs. 1 and 2 and constructed generally similar to the same.

`In the embodiment of the invention which I have chosen to illustrate and describe the same, the grinding wheel may be mounted upon the ydrive shaft 12 of an electric motor 14, the shaft 12 being screw-threaded at the end to receive a locking nut ,16,

The grinding wheel may generally include a pair yof mounting plates 18 and 20 similar to disc wheel members,

frice the plates having the openings 21 therein .to receive the shat 12. The mounting plates .18 and 20 are also provided with outwardly rturned llanges .at 22 and 24 so that the plates are spaced apart the thick-ness of a pair-of side walls 26 and 28 of a rubber tread 30 which is .fastened therebetween. Each of the llattenedpo-rtions 18a and 20a of .the mounting plates 18 and 20 is provided with a plurality of lopenings to receive the fastening bolts 32, the same passing through similar .openings in the side walls 26 and 28 of the tread member 30 and the assembly being securely fastened together by means `of lock nuts 34.

Each of the side walls 26 and |28 of the tread member is also provided yWi-th an outwardly projecting peripheral ridge 36 adapted to 'be received in a complementary peripheral groove 38 in the Afacing walls of each of fthe mounting plates 18 and 20.

The tread 30 which has the side walls 26 and 28 also has a peripheral or face flange 40 having a Ithickness sufficient to have a plurality of cross-pins 42 mounted therein, the cross-pins being adapted to .enten-d beyond Ithe edges of the tread member and engage in elongated openings 44 in the mounting plates 18 :and 20. The peripheral tread portion 40 'is also yformed with an enlarged medial portion 40a spa-ced between the mounting plates 18 and 20, :the side walls 26 and 28 also having an annular ridge 46 therein so that when the grinding wheel is subjected lto a comparatively high rotational speed, cent-ritutgal force will .tend to swing out the tread portion 40 thereof to a slightly larger diameter, thus effectively tightening the .abrasive band B Ion the same. At the same itime, the outward thrust of the tread portion 40 tof the grinding wheel is .controlled in a radial direction by means of the pin members 42 that are guided in this movement in the elongated slots 44. Concentric rows of openings 48 and 50 may be formed in each of the mounting plates 18 and 20 so that heat generated in the rubber of the grinding wheel may be dissipated to atmosphere, thus giving the grinding wheel :a longer lite and making ift more efcient in use.

In Figs. l and 2 I have shown a form of the invention in a comparatively small size; the grinding wheel shown is approximately 7 inches in diameter, and for grinding wheels of this size and upward this construction may be employed. However, for larger grinding wheels I prefer to employ the construction shown in Fig. 3 wherein the tread member 30 may have a portion of the facing surfaces of the side walls 26 and 28 vulcanized together as shown at V, and the tread may be provided with an air valve 70 communicating with the chamber 72 formed in the interior of the side walls 26, 28, and the peripheral facing tread portion 40.

With this construction, annular ridges 74 and 76 are provided in each of the side walls 26 and 28 of the tread member so that either from centrifugal force or by directly applied air pressure the peripheral surface of the tread member may be expanded to a larger diameter, the same again being controlled by the pin members 42 that extend into elongated slots t4 in each of the mounting plates 18 and 20. The mounting plates may also be provided with concentric rows of openings for permitting heat generated in the rubber of the grinding wheel to be dissipated, as also shown in Figs. 1 and 2.

Wit-h the foregoing construction it can be seen that I have provided a highly improved construction of grinding wheel and one in which, by the use of the guide pins vulcanized in the rubber treads, the peripheral tread will also be held in place even though the sanding belt may become loose or broken in use. In addition, by the provision of more backing through the center of the tread portion, there will be less tendency in the starting for a backlash or swinging of the tread in the mounting plate.

While I have illustrated and described a specific embodiment of the invention, it will be apparent to those skilled in the art that changes and modications may `be made in the exact details shown and I do not wish to be limited in `any particular; rather what I desire to Vsecure and protect v.by Letters Patent ofzthe 'United States .isz

4l. AAn abrasive wheel of the Yclass -described comprising a shaft, a pair of .similarly shaped circular mounting plates secured together axially about said -shaft and ,then ared outwardly, a .rubber .tread .portion ,having side -.walls extendingdownwardly and positioned between said mounting plates, said side walls .vulcanized together to -form an .air-tight chamber, an air lvalve associated therewith, each of said mounting plates having la .circular groove therein and each of said ,-sidewallsofsaid tread portion having a -ridgetengaging said groove, said :tread portion havingrafateircular edge and an-abrasive bandsecured about ,its periphery, `said mounting plates having a ,plurality of aligned elongated holes disposed .about the iperiphery of the same and said tread portion having ,pin members extendingtherethrough and engaging saidelongatedholes.

2. An. abrasive vwheelofzthe class. described vcomprising a'shaft, Vazpair of rsimilarly shaped :mounting plates secured together and Yon said shaft, .a tread portion having side walls :extending downwardly and positioned .between said mounting fplates, leach of said ymounting plates .having 1a circulargroove dtherein andeach kof the sidewalls of'said tread :portion having a ridge engagingsaid groove, said tread .portion having an abrasive Vband secured about its periphery, `said mounting plates .and side walls of said tread portionbolted togetheraroundwsaid .shaft .within said circular Aridge andgroove fastening'between the same.

A'2a. An .abrasive wheel of the class desscribed comprising a shaft,a pair of similarly-shaped circular mounting plates secured-together axially-about said shaft and then ared rvoutwardly, a rubber tread portion having side walls extending downwardly and positioned between Vsaid mounting plates, said side walls vulcanized together t0 form an air-tight chamber, an air valve associated Vthere- With, each of said-mountingplates-having a circular groove thereinand-each of said side walls of saidrtreadgportion having a ridge engaging said groove, saidtread portion havingan abrasive band secured aboutits periphery, Asaid mounting plates having a plurality `of aligned Aelongated holes disposed aboutt-he periphery of the same and said tread portion'having pin members extending therethrough and engagingsaid elongated holes.

4. An'abrasive wheel-of the class described comprising a shaft, a pair of similarly shaped mounting plates secured together vand 4on said shaft, said plates having Voutwardly turned curved portions 'terminating in parallel spacedalignment, afrubber tread portion 'having'side walls extendingrdownwardly and-positioned between said-mounting plates, each of said mounting plates having a circular groove therein and each of said side walls of said tread portion having a ridge engaging said groove, said tread portion having a dat circular edge and an abrasive band secured about the same, the lower edges of said side walls of said tread portion being vulcanized together, said plates and side walls of said tread portion having a circular row of aligned holes therethrough within said ridge and groove connection and fastening bolts. positioned through said aligned holes.

5. An abrasive .wheelofthe Lclass :describedcomprising a shaft, arpair of similarly shaped mounting plates secured togetherand on Ksaid shaft, said plates having outwardly turned curved portions iterminating Yin parallel spaced alignment, a rubber tread portion having side walls extending downwardly and positioned between said mounting plates, each of said mounting plates having a circular groovetherein.andeachof said side .walls of said.tread portion 'having a ridge engaging said groove, said tread portion thaving .a ,flat .circular .edge and .an .abrasive band secured .about the same, ;the lower .edges of .said rside wallsofsaid tread portion being .vulcanized together, said plates and Vside wallstof said tread .portion having a-cirvcular 4row of V,aligned holes therethrough within said ridge andfgrooveconnectionand.fastening bolts positioned through saidaligned holes, the flat ,circular Ledge of `said tread portion having ,transverse pin members Vextending therethrough ,andfelongated i holes4 in said;rnounting :plates to receive theends-,of said pinmembers.

6. An abrasive wheel .ofthe classdescribedcornprising a-shaft, a,pairfosimilarlysshaped mountingfp'lates secured together and on said shaft, said plates having outwardly turned curved portions .terminating .fin parallel spaced alignment, a :rubber tread :portion having side .walls extending downwardlyZ and: positioned betweensaid. mounting plates, each vof said ,mounting plates havinga circular groove .therein and .each of said side wallsof said tread portion :having a ridge iengaging said groove, said tread portionhavingafat circular edge and an abrasive band secured aboutthesameftherlower. edges ofsaid .side walls of said ltread portion Jbeing jvulcanized together, said plates and side walls of said tread portion lhaving a circular row of .aligned holestherethrough within-said ridge and .groove "connection .and fastening bolts positioned through said aligned holes, the `flat-circular edge ofsaid tread portion having transverse pinmernbers extending therethrough and-elongated fholes in said mountingplates to receive the ends of said -pinmembersysaid'flat circular edge-ofssaidftread portion -having a^medial inwa1dly extending bulge l'throughout its circumference.

Noreferences cited. 

